How Many Stars are in the Universe?
Scientists estimate that there are between 3 and 7 x 1022 stars in the universe, or between 30 and 70 billion trillion. This is actually a relatively small number by some standards. For instance, the number of atoms in the Earth is roughly 1050, and the number of atoms in Mt. Everest is about 1040. The number of atoms in half a kilogram of rock is roughly 1025. Avogadro’s number, which represents the number of atoms in 12 grams of carbon, is about 6 x 1023. The stars in the universe are aggregated into many layers of organization — beginning with star clusters, which coalesce in galaxies, which are members of galaxy clusters, which are in turn members of superclusters, which are in turn members of super-superclusters, all the way up to the largest features in the universe, such as the Great Wall, a galactic supercluster which is about half a billion light-years long, a third of a billion light-years wide, and 15 million light-years thick. At its highest level of organization, the gala
